Diacetoxyiodobenzene assisted C–O bond formation via sequential acylation and deacylation process: synthesis of benzoxazole amides and their mechanistic study by DFT

2016 ◽  
Vol 14 (32) ◽  
pp. 7735-7745 ◽  
Author(s):  
Lokendrajit Nahakpam ◽  
Francis A. S. Chipem ◽  
Brajakishor S. Chingakham ◽  
Warjeet S. Laitonjam

An efficient method for the transformation of N-substituted-N′-benzoylthioureas to substituted N-benzoxazol-2-yl-amides due to oxidative dehydrogenation by diacetoxyiodobenzene.

Author(s):  
Zhiying Fan ◽  
Zhifan Wang ◽  
Ruoyi Shi ◽  
Yuanhua Wang

Unlike C-N bond formation with classical dirhodium(II)-nitrenoids as the key intermediate, dirhodium(II)-catalyzed 1,2-and 1,3-diamination reactions are realized by a free radical mechanism. A mechanistic study revealed that the reactions undergo...


2020 ◽  
Author(s):  
Angus Voice ◽  
Gary Tresadern ◽  
Rebecca Twidale ◽  
Herman Van Vlijmen ◽  
Adrian Mulholland

<p>Ibrutinib is the first covalent inhibitor of Bruton’s tyrosine kinase (BTK) to be used in the treatment of B-cell cancers. Understanding the mechanism of covalent inhibition is crucial for the design of safer and more selective covalent inhibitors that target BTK. There are questions surrounding the precise mechanism of covalent bond formation in BTK as there is no appropriate active site residue that can act as a base to deprotonate the cysteine thiol prior to covalent bond formation. To address this, we have investigated several mechanistic pathways of covalent modification of C481 in BTK by ibrutinib using QM/MM reaction simulations. The lowest energy pathway we identified involves a direct proton transfer from C481 to the acrylamide warhead in ibrutinib, followed by covalent bond formation to form an enol intermediate. There is a subsequent rate-limiting keto-enol tautomerisation step (DG<sup>‡</sup>=10.5 kcal mol<sup>-1</sup>) to reach the inactivated BTK/ibrutinib complex. Our results represent the first mechanistic study of BTK inactivation by ibrutinib to consider multiple mechanistic pathways. These findings should aid in the design of covalent drugs that target BTK and related proteins. </p>


RSC Advances ◽  
2018 ◽  
Vol 8 (39) ◽  
pp. 22122-22126 ◽  
Author(s):  
Raveendra Jillella ◽  
Chang Ho Oh

Copper-catalyzed domino cyclization of 2-alkynylanilines followed by C–C bond formation with quinones is an efficient method of accessing 3-indolyl quinones.


2019 ◽  
Vol 17 (12) ◽  
pp. 3239-3248 ◽  
Author(s):  
Satish G. More ◽  
Gurunath Suryavanshi

An efficient method for metal-free C–C bond formation between p-quinone methides (p-QMs) and cyclic ethers via a radical pathway to afford substituted diarylmethanes and triarylmethanes or to effect the α-alkylation of the cyclic ethers has been developed.


ChemInform ◽  
2010 ◽  
Vol 30 (34) ◽  
pp. no-no
Author(s):  
Masaaki Ueki ◽  
Takayoshi Ikeo ◽  
Kumiko Hokari ◽  
Keiko Nakamura ◽  
Akihiko Saeki ◽  
...  

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